The Brain Teaser: Scroll Down for your Solution
Picture an empty wine bottle with a cork secured at the top in the usual way. Inside the bottle a metal ring hangs suspended by a string. How is it possible to make the metal ring drop to the bottom of the bottle without touching the ring, the thread, the cork, or the bottle while leaving the cork in place and intact?
By using a magnifying glass and the suns rays you could burn through the string and consequently cause the ring to drop to the bottom of the bottle.